Solar eclipse of July 11, 1991

A total solar eclipse occurred at the Moon's descending node of orbit on Thursday, July 11, 1991, with a magnitude of 1.08. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moon's apparent diameter is larger than the Sun's, blocking all direct sunlight, turning day into darkness. Totality occurs in a narrow path across Earth's surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. Totality began over the Pacific Ocean and Hawaii moving across Mexico, down through Central America and across South America ending over Brazil. It lasted for 6 minutes and 53.08 seconds at the point of maximum eclipse. There will not be a longer total eclipse until June 13, 2132. This was the largest total solar eclipse of Solar Saros series 136.

This eclipse was the most central total eclipse in 800 years, with a gamma of -.0041. There will not be a more central eclipse for another 800 years. Its magnitude was also greater than any eclipse since the 6th century.

Observations
An observation team funded by the National Natural Science Foundation of China made near-infrared spectroscopic observations in the southern suburbs of La Paz, Baja California Sur, Mexico. Weather was clear on the eclipse day in La Paz. The team captured dozens of frames of the slitless spectrum of the upper layer of photosphere and chromosphere, and the slit spectrum outside the solar surface. They also captured images of the chromosphere and solar prominences. Among the professional observation teams from various countries to La Paz, six used the new CCD sensors for the first time in solar eclipse observation. Among them, the Chinese and Japanese team used it to observe long-wavelength spectra. A team of 320 people from NASA's Johnson Space Center made observation in Mazatlán, Mexico. The local weather was not ideal in the days before the eclipse, but got slightly better as the eclipse day approached. Some people went to San Blas, Nayarit for better weather conditions. In the end, a hole in the clouds appeared in El Cid in western Mazatlan, through which the corona and prominences was visible. Other observers 1 to 5 miles away were clouded out. In San Blas, the corona and prominences were still visible, even though the clouds became thicker during totality. Scientists from the Royal Observatory of Belgium, the Institute of Geodesy and Geophysics of the Chinese Academy of Sciences, and the Institute of Geophysics of the National Autonomous University of Mexico made observations in Mexico City to study the change in gravity during a total solar eclipse.

Alleged ancient Maya prediction
The American ethnographer and anthropologist Victoria Bricker and her late husband and colleague Harvey Bricker, claim in their book "Astronomy in the Maya Codices" that by decoding pre-Columbian glyphs from the four Maya codices they discovered that pre-16th century Maya astronomers predicted the solar eclipse of July 11, 1991. In their 2011 volume, the husband-wife Brickers team explain how they translated the dates from the Maya calendar, then used modern scientific knowledge of planetary orbits to line up the data from the Maya prediction with the Gregorian calendar. Reviewers disputed the claim in 2014, concluding that, "loose hieroglyphic readings and accommodating pattern matching occurs throughout the book."

In popular culture
The 1991 eclipse appears in the music video for Cosas del Amor, a duet by Vikki Carr and Ana Gabriel.

Eclipses in 1991

 * An annular solar eclipse on January 15, 1991.
 * A penumbral lunar eclipse on January 30, 1991.
 * A penumbral lunar eclipse on June 27, 1991.
 * A total solar eclipse on July 11, 1991.
 * A penumbral lunar eclipse on July 26, 1991.
 * A partial lunar eclipse on December 21, 1991.

Metonic

 * Preceded by: Solar eclipse of September 23, 1987
 * Followed by: Solar eclipse of April 29, 1995

Tzolkinex

 * Preceded by: Solar eclipse of May 30, 1984
 * Followed by: Solar eclipse of August 22, 1998

Half-Saros

 * Preceded by: Lunar eclipse of July 6, 1982
 * Followed by: Lunar eclipse of July 16, 2000

Tritos

 * Preceded by: Solar eclipse of August 10, 1980
 * Followed by: Solar eclipse of June 10, 2002

Solar Saros 136

 * Preceded by: Solar eclipse of June 30, 1973
 * Followed by: Solar eclipse of July 22, 2009

Inex

 * Preceded by: Solar eclipse of July 31, 1962
 * Followed by: Solar eclipse of June 21, 2020

Triad

 * Preceded by: Solar eclipse of September 9, 1904
 * Followed by: Solar eclipse of May 11, 2078